Tandem mill.



No. 876,895. PATENTED JAN.14, 1908. C. W. BRAY.

TANDEM MILL.

APPLICATION FILED 1423.9, 1905.

SSHEETS-SHEBT l.

W] NE UNITED STATES PATENT4 OFFICE.

CHARLES W. BRAY, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO AMERICAN SHEET `t TIN PLATE COMPANY, OF PITTSBURG, PENNSYLVANIA, A CORPORATION OF NEW JERSEY.

TANDEM MILL.

Specification of Letters Patent.

Patented Jan. 14, 1908.

T o all whom it may concern.'

Be it known that I, CHARLES W. BRAY, of Pittsburg, Allegheny county, Pennsylvania, have invented a new and useful Tandem Mill, of which the following is a full, clear, and exactdescription, reference being had to the accompanying drawings, forming part of this specification, in which,-

Figure l is a sectional plan viewshowing a tandem mill for rolling sheets or plates from sheet bars or tin bars, constructed in accordance with my invention Fig. 2 isl a sectional front elevation of one of the balanced mills; and Fig. 3 is an end elevation of the same.

My invention relates to the rolling of sheets or lates from bars or slabs in tandem mills, an is designed to overcome certain difficulties which have been experienced in the use of tandem mills for such purpose.

I-leretofore in using tandem mills for rolling sheets or lates from slabs, sheet bars, tin bars, and similar articles, the lower roll of each set has been positively driven, while the upper roll is a jump roll driven only by friction, having no positive driving connections. In such mills, I have found in lpractice that owing to the. thickness of the metal passing 'through the first sets of rolls there is anexcessive amount of back-lash and slip ing as the. bar or slab entersv the set of rolls. In this type of mill, the jump roll normally rests upon and is driven frictionally by the lower positively-driven roll, and when the slab or bar is fed in, the upper roll is forced up and the bar or slab stops momentarily, producing excessive shocks and jars on the driving connections for the lower rolls; at the same time the speed of the upper roll is reduced and as it then picks up-rlts speed it slips upon the metal 'passing t ough, since the metal is at this time feeding at a higher rate of speed than the speed ofthe u ler roll.

Myl invention overcomes .these culties, and it consists in providing a tandem mill in which the top and bottom rolls of at least the irst set or setsof rolls are both ositively driven, and the upper roll is prefera ly counter-balanced, the succeeding rolls being having six sets of rolls, 2, 3, 4, 5, 6, and 7. I

of the sets 5 and 7 respectively.

In the drawings, I show a tandem mill have shown these sets as divided into two groups of three each, each group being driven from a common shaft. 'lhus the .sets of rolls 5, 6 and 7 are driven from the common shaft 8 having wabbler connections with the shaft 9 carrying the gear 10. This gear intermeshes with idler gears 11, 12, which in turn engage the driving gears 13 and 14. The shaft 9 of the gear 1() has a wabbler connection with the lower roll of the set 6, while the shafts of the gears 13 and 14 have corresponding connections with the lower rolls v The other group is driven from the shaft 15 having the gear 16 intermeshing with the idler gears 17 and 18. These idle'r gears intermesh with the driving gears 19 and 20. The gear 20 is directly connected to the lower roll of the set .4 through the wabbler connections. The

housin s. Vwith t e inner end of the frame, while the shaft 15 of the gear 16 and the shaft 21 of the gear 1-9 have Wabbler connections with the lower pinions of the pinion sets 22 and 23. The lower pinion of each set has wabblex` connection with the lower roll of lone of the first two sets of rolls, while the upper pinion is similarly connected to the corresponding upper roll. I thus ositively drive both the u per and lower `ro ls 'of the iirst two sets. The apparatus shown is speciall designed for the rolling of sheet bars into s eets; and it will be understood' that the number of sets of rolls in which both the upper and lower rolls are positively driven may be more or less than shown, and may comprise each set of the mill. v l

Each set of rolls 2 and 3 is of the type shown in Figs. 2 and 3, in which I illustrate the iirst set. The upper roll 2 of each of these sets is carried in bearings which are connected by pairs of vertical rods 24 with a lever frame 25 pivoted on links 26 pivotallyconnected to the bottom portions of the The rods 24 are loosely connected outer end of theframeis provided with a counterbalancingl Weight 27. These Weights are of sufficient size to hold the upper roll apart from the lower roll when the screws are positioned to allowit. In other Words, the Weights cause thebearings of the upg-pr roll to olloW the screws using the apparatus the slabs, sheet. bars or tin bars are fed singly and succes- 55 what tothe expense of the sively through the tandem sets of rolls. A number of bars will be in the mill at the same time, so that part of the bars will be passing through the balanced mill at the same time that others are passing through the jump rolls. When a slab or bar is fed into the iirst set of rolls 2 there will be -no momentary stoppage or slipping such as in the jump roll type, since the top roll is positively .driven and the rolls therefore act upon both faces of the plate to feed it forward and reduce it. The counter-balancing aids in preventing jars and shocks upon the driving connections, since the upper roll is not forced\ vertically by the metal as it enters, except to a very small degree. After passin through the sets of positively driven ro ls, the metalis reduced to such a thickness that it can enter the set of rolls l without any serious slipping or jars. From this point on through the successive rolls the jump rolls act in the ordinary manner, if such are used.

The advantages of my invention result from using sets of rolls in which both the top and bottom` rolls are positively driven for at least the rst sets of a tandem mill. l thus avoid the troubles resulting from the 1 jumping of rolls under the action of a heavy piece of metal, making the mill lon er lived, and decreasing the amount of reaka e and repairs. The, mill runs moresmooth y and with better results and uniformity.

All of the sets of the mill may be arran ed with positively driven top and bottom ro ls,.

the counter-balancing feature may be used ornot as desired, and many other variations may be made in the form and arrangement of the rolls and their connections without departing from my invention.

, l. A tandem sheet or plate mill having a erases driven upper and lower rolls; substantially as described.

3. A tandem sheet or plate mill having a y plurality of two-high sets of' plain-faced rolls, each set having positivedriving connections for the upper and lower roll, the upper roll being counter-balanced; substantially as described.

4. A tandem sheet or plate mill consisting of two-high sets of rolls, having yat least one of the Viirst sets provided with positive driving connections for the upper and lower rolls, and succeeding sets having a positivelydriven lower roll and an upper jump roll, said rolls being plain-faced; substantially as described.

5. A tandem sheet or plate mill having at least two two-high sets of plain-faced rolls with intermeshingdriving gears common to both, at least one of said sets having positively-driven upper and lower rolls; substantially as described.

6'. A tandem sheet or plate mill having a two-high set of rolls with positively driven upper and lower plain-faced rolls and -a succeeding two-high set with a positively-driven lower roll and an upper jump roll, a gear havingdirect'connections to the lower roll of' the second set and a gear connected to driving pinions which in turn are connected to the upper and lower rolls of the irst'set; substantially as described.

ln testimony whereof, l have hereunto set/my hand.

" CHARLES vv. BRAY.

Witnesses: y y

G. C. KIMBALL, S. A. DAvIs. 

